When you see someone you know, the easiest way to recognize them is by their face—but not everyone can do this. Many people have prosopagnosia, or face blindness, which is a neurological（神经病学的）condition where the part of the brain that recognizes faces fails to develop. It can stop people recognizing partners, family members, friends or even their own reflection. It was once thought to be caused by brain injury (acquired prosopagnosia) but now a genetic link has been proved (development prosopagnosia).

    Acquired prosopagnosia is a very rare but as many as one in 50 people may have developmental prosopagnosia. There's no specific treatment, but training programmes are being developed to help improve facial recognition.

    For many, the situation can be dangerous. I've heard stories of people being robbed by strangers claiming to be family members, or of children wandering off strange men.

    It was only is this century that researchers began to realize exactly how many people in this world were quietly living with the condition.

    Like a blind person who can recognize family members by their footsteps, prosopagnosics are forced to develop unusual ways of discovering who it is they're meeting or talking to. From the obvious markers like hair and voice, to the way one sits, stands or walks, they rely on dozens of means to get through ordinary life.

    Faces are an important part of identity. Not to be recognized feels terrible—it's as if you've been overlooked, like someone's saying you don't matter. But it's nothing to the pain of knowing that you're hurting people's feelings constantly, and yet being completely unaware that you're doing it in the moment. To be alienated（隔离的）from the world of faces is a strange position to be in, but I'm comforted by the thought that articles like this will do a little to help people forgive me and others like me.

    There are many reasons why people can't get a good night's sleep and as with any other health conditions, things are not likely to improve until you find a way to break the cycle.

    These are some of the main factors that need to be addressed.

    Worry and stress

    We have all been kept awake by many factors that cause worry and stress in our lives. Money problems, relationship issues and work stresses can have you sitting up all night. A useful habit is to download your thoughts at the end of the day. Keep a pen and paper next to your bed and before you go to sleep, write down your thought and worries, create a to-do list for the following day or set down solutions and ideas that relate to work.

    Diet and eating patterns

    What and when you eat can have a major impact on your ability to sleep. Eating too late or indulging in a rich or spicy meal can keep you awake. These foods take a long while to digest and the after effects of indigestion and heartburn are not going to set you up well for a good quality sleep.

    A research suggests that both calcium and magnesium may be linked to poor sleep. Even low intakes of magnesium found in green vegetables, beans, nuts and seeds have been shown to make it harder to stay asleep. Calcium is found in dairy foods, soybeans and green vegetables and low levels have also been shown to make it more difficult to nod off.

    Alcohol and caffeine

    Tea, coffee and energy drinks contain caffeine that helps to stimulate the nervous system and make you more alert, which is great if you need a pick-me-up. Dosing up on caffeine during the day can affect your ability to sleep later on in the evening. Try limiting your intake of caffeine to the morning and switch to decaffeinated options such as herbal teas. Alcohol is a double-edged sword when it comes to sleep. While a little may help to induce slumber, even in small amounts it can cause fragmented sleep patterns.

    Bedroom environment

    “Your bedroom should be dark once the lights are switched off because melatonin, a sleep-regulating hormone, is very light-sensitive. Maintaining the right temperature can also help with sleep as a room that is too hot may prevent your core temperature from going down, which is essential for switching on the sleep mechanism within the body.

    The world is filled with smart ，educated and gifted people. We meet them every day. A few days ago ，my car was not running well. I pulled it into a garage and the young mechanic fixed it in just a few minutes. He knew what was wrong by simply listening to the engine sound. I was amazed. The sad truth is that great talent is not enough.

    I am constantly shocked at how little talented people earn. I heard the other day that less than 5 percent of Americans earn more than $100，000 a year. A business consultant who specializes in the medical trade told me how many doctors and dentists struggle financially. It was this business consultant （顾问）who gave me the phrase ，“They are one skill away from great wealth.”

    There is an old saying that goes，“JOB means  'Just Over Broke（破产）”. And unfortunately，I would say that the saying applies to millions of people. Because schools do not think financial intelligence is intelligence，most workers “live within their means”. They work and they pay the bills. Instead I recommend that young people seek work for what they will learn ，more than what they will earn.

    When I ask the classes I teach ，“How many of you can cook a better hamburger than McDonald's ？ ” almost all the students raise their hands.I then ask ，“So if most of you can cook a better hamburger ，how come McDonald's makes more money than you？” The answer is obvious: McDonald's is excellent at business systems.The world is filled with talented poor people.They focus on perfecting their skills at building a better hamburger rather than the skills of selling and delivering the hamburger.

    These are instructions for making invisible ink using baking soda.

    Almost every second of every day an older adult falls in the United States. That's approximately 29 million falls per year and nearly 27, 000 deaths, according to the Centers for Disease Control and Prevention.

    Still in the stating stage, the Active Pelvis Orthosis (APO) system in Switzerland wants to make a lightweight, wearable exoskeleton (外骨骼) that could detect signs of balance loss and assist with balance recovery to keep the elderly wearer from falling, only when needed.

    Other exoskeletons, either in development or on the market today, assist with movement and make heavy objects feel lighter. Mobility-impaired people can walk again. But none of these devices predict what the wearer is going to do next and take measures to correct an unsteady move.

    The 3 kilogram (6.7 pound) exoskeleton was built entirely from scratch by the research team and is designed to be worn on the lower half of the body. A waistband connects to two movable carbon fiber braces (支架), each one positioned on the outer side of a leg. Tiny motors and so-called "adaptive oscillators" (适配振荡器) in the computer circuits use a special process to detect the, wearer's unique paces. That part takes just a few minutes.

    While wearing the exoskeleton, a person may feel the braces and the motors pushing slightly on their legs. If their paces go against normal, the motors create a force in the braces that cause them to stiffen up and push a little more strongly against the legs, which provides stability.

    In the next three years, the APO hopes to develop something that is commercially available.

    If you're DIY-minded, you can build your own solar power system. In some cases, you can even build your own solar panels (电池板), although the amount that you can effectively DIY home solar depends on how much you want to power. Making your own solar panel is a time-consuming process and requires some electrical skills. However, it can also be very rewarding-learning to build your own panel is a great way to understand how solarelectricity is generated.

    Before you can build your own solar panels, you first need to understand how solar cells generate electricity. Once you've bought individual solar cells (they can be purchased online), the basic process for building your own solar panel goes like this: Prepare the backing for your panel. Many DIY solar panel builders prefer to use a wooden board as the base for their solar cell. You'll need to drill holes in the board so that the wires for each cell can pass through. Wire your solar cells together. This requires some experience with electrical work. Use a soldering iron (烙铁) to attach wire to the solar cells and then link each of the cells together. Attach cells to your backing. If possible, attach each solar cell to the backing individually. This makes it easier to replace a single cell in the event that becomes damaged or is not operating properly.

    At this point you have a functional solar panel that can produce electricity when the sun shines. However, a solar panel by itself is not useful. If you are trying to generate electricity to power devices in your home, you need to pair your panel with an inverter (换流器) that will turn direct current (DC) power from the sun into the alternating current (AC) power used in most modern electronic devices.